NSClient++ :: Failed to establish secure connection

Question

Trying to get active checks of a Windows host from my nagios server. At this point I'm not even using nagios, and just running check_nt from the command line.

• Verified that the port is open, it allows telnet
• Ensured insecure mode is configured within nsclient.ini
• Ensured connecting host is entered in "allowed hosts"
• At this point, security is not a concern, so encryption/passwords/etc are not needed or wanted.
• For troubleshooting I'm just running the "CLIENTVERSION" command since it's simple
• I've ensured the nsclient++ service has "allow interaction with desktop" option.

Here is the command I'm using from the allowed host:

check_nt -H 10.10.5.200 -p 12489 -v CLIENTVERSION

This is the output:

[root@nagioshost]# /usr/lib64/nagios/plugins/check_nt -H 10.10.5.200 -p 12489 -v CLIENTVERSION
No data was received from host!
could not fetch information from server

Running 'nscp test' I can see the connection come in but it fails:

D       nrpe Accepting connection from: 10.10.7.101, count=1
E       nrpe Failed to establish secure connection: short read: 219
                    c:\source\nscp\include\socket/connection.hpp:243

Here is my nsclient.ini fields

[/settings/default]
password = Me0zf92h7f
allowed hosts = 10.10.7.101



[/settings/NRPE/server]
verify mode = none
port = 12489
insecure = true



[/modules]
CheckExternalScripts = 1
CheckHelpers = 1
CheckEventLog = 1
CheckNSCP = 1
CheckDisk = 1
CheckSystem = 1
NRPEServer = 1

Solution

check_nrpe is for NRPEServer and check_nt is for NSCLientServer

So you need to move your configuration over to the NSClientServer module for check_nt to work or better yet stop using check_nt and move over to check_nrpe*.

[/settings/default]
password = Me0zf92h7f
allowed hosts = 10.10.7.101

[/settings/NSClient/server]
port = 12489

[/modules]
CheckExternalScripts = 1
CheckHelpers = 1
CheckEventLog = 1
CheckNSCP = 1
CheckDisk = 1
CheckSystem = 1
NSClientServer = 1

• check_nt is very limited in comparison to check_nrpe.

Comments

[Diamond]

What if you just run: check_nrpe -H 10.10.5.200 from the allowed host? This will show if nrpe is properly configured. Also comment out the line with password, and restart nsclient and then check again with check_nt. docs.nsclient.org/tutorial/nagios/check_nt.html

[emmdee]

Thanks, yes check_nrpe worked perfectly. This is solved and answer marked. Appreciate your input!!

[emmdee]

I was able to get this working with check_nrpe with little effort -- Thanks! Here is working command I used. /usr/lib64/nagios/plugins/check_nrpe -H 10.10.5.200 -p 12489 -c check_drivesize -a drive="E" warn="used>75%" crit="used>90%" Once this was working I simply converted to a Nagios command/service definition and now I'm checking the drive as I needed.